To natively compile aGrUM, you can use the "Homebrew":http://brew.sh package manager for OS X.
Install Homebrew. Be carefull of the requirements (in particular XCode and Command Line Tools for Xcode).
Installation of needed HomeBrew packages :
brew install bash coreutils git cmake
Then set your environment. For example, if you installed gcc-4.9 using Homebrew:
export CC=$(which clang) export CXX=$(which clang++)
Now the installation is the same as for Linux :
git clone git://forge.lip6.fr/aGrUM cd aGrUM python act install release aGrUM --static -d INSTALL_PATH